Chapter 50 - Cerebral.pdf

UNIT 12 Health Conditions of Children 50 Neurological Conditions Joley Johnstone Originating US chapter by Cheryl C. Rodgers http://evolve.elsevier.com/Canada/Perry/maternal OBJECTIVES On completion of this chapter the reader will be able to: 1. Describe the various modalities for assessment of ce...

UNIT 12 Health Conditions of Children 50 Neurological Conditions Joley Johnstone Originating US chapter by Cheryl C. Rodgers http://evolve.elsevier.com/Canada/Perry/maternal OBJECTIVES On completion of this chapter the reader will be able to: 1. Describe the various modalities for assessment of cerebral function. 2. Differentiate between the states of consciousness. 3. Formulate a care plan for the child with altered level of consciousness. 4. Distinguish between the types of head injuries and potential complications. 5. Describe the nursing care of a child with a tumour of the central nervous system. 6. Outline a care plan for the child with bacterial meningitis. 7. Differentiate between the various types of seizure characteristics. 8. Demonstrate an understanding of the manifestations of a seizure disorder and the management of a child with such a disorder. 9. Describe the preoperative and postoperative care of a child with hydrocephalus. Most of the information about the status of the brain can be obtained by observation and indirect measurements. Some of these measurements are discussed elsewhere in relation to numerous aspects of child care (e.g., as part of the health assessment [Chapter 33], newborn status [Chapter 26], intellectual disability [Chapter 42], cerebral palsy [Chapter 54], and attainment of developmental milestones at each stage of development). Head trauma, increased intracranial pressure (ICP) and altered states of consciousness are common disorders of pediatric neurological dysfunction, thus they are described here, as well as techniques for neurological assessment and interpretation of diagnostic tests. addition, valuable information is gained by eliciting progressively sophisticated communicative and adaptive behaviours. Delay or deviation from expected developmental milestones helps identify children at high risk for neurological issues or developmental delay. Persistence or reappearance of reflexes that normally disappear may indicate a pathological condition. In evaluating the infant or young child, it is also important to obtain the pregnancy and birth history to determine the possible impact of intrauterine environmental influences known to affect the maturation of the central nervous system (CNS). These influences could include maternal infections, cigarette or alcohol consumption, drug use, toxin exposure, trauma, and metabolic insults. General aspects of assessment that provide clues to the etiology of a neurological condition include the following: Family history—Identifies possible inherited genetic disorders with neurological manifestations Health history—May provide valuable clues regarding the cause of dysfunction. Information should include Apgar scores, age of developmental milestones, trauma or injuries, acute and chronic illnesses, encounters with animals or insects, and ingestion or inhalation of neurotoxic substances. Physical examination—Includes assessment of the following: • Level of alertness • Size and shape of the head, including presence of fontanels • Sensory responses • Motor function, including posture, tone, and muscle strength ASSESSMENT OF CEREBRAL FUNCTION General Aspects Children younger than 2 years of age require special evaluation for neurological assessment, as they are unable to respond to directions designed to elicit specific responses. Early neurological responses in infants are primarily reflexive. These responses are gradually replaced by meaningful movement in the characteristic cephalocaudal direction of development. This evidence of progressive maturation reflects more extensive myelination of the neurons and changes in neurochemical and electrophysiological properties. Most information about infants and small children is gained by observing their spontaneous and elicited reflex responses as they develop increasingly complex locomotor and fine motor skills. In 1336 CHAPTER 50 Superior sagittal sinus (of dura) Neurological Conditions Epidural space Periosteum Dura mater Galea aponeurotica (periosteum) 1337 One functional layer Arachnoid Subdural space Subarachnoid space Skull Falx cerebri Skin Pia mater Muscle Lateral ventricle Corpus callosum Third ventricle Fig. 50.1 Coronal section of the top of the head showing meningeal layers. (From Patton, K. T., & Thibodeau, G. A. [2010]. Anatomy and physiology [7th ed.]. Mosby.) • Motility, including symmetry of movements and involuntary movements • Respirations, including signs of prolonged apnea, ataxic breathing, paradoxical chest movement, or hyperventilation • Dysmorphic facial features • Behavioural cues, including consolability and habituation • Primitive and deep tendon reflexes • Cranial nerves, testing for function (see Chapter 33) Increased Intracranial Pressure The brain, tightly enclosed in the solid bony cranium, is well protected but highly vulnerable to pressure that may accumulate within the enclosure (Figure 50.1). The cranium’s total volume—brain (80%), cerebrospinal fluid (CSF) (10%), and blood (10%)—must remain approximately the same at all times. A change in the proportional volume of one of these components (e.g., an increase or decrease in intracranial blood) must be accompanied by a compensatory change in another. In this way, the volume and pressure normally remain constant. Examples of compensatory changes are reduction in blood volume, decrease in CSF production, increase in CSF absorption, or shrinkage of brain mass by displacement of intracellular fluid and extracellular fluid. Children with open fontanels compensate by skull expansion and widened sutures. However, at any age the capacity for spatial compensation is limited. An increase in ICP may be caused by tumours or other spaceoccupying lesions, accumulation of fluid within the ventricular system, bleeding, or edema of cerebral tissues. Once compensation is exhausted, any further increase in volume will result in a rapid rise in ICP. Early signs and symptoms of increased ICP are often subtle and assume many patterns (Box 50.1). As ICP increases, signs and symptoms such as headache and vomiting become more pronounced and the level of consciousness (LOC) deteriorates. Altered States of Consciousness Consciousness implies awareness—the ability to respond to sensory stimuli and have subjective experiences. Consciousness has two components: alertness, an arousal-waking state, including the ability to respond to stimuli; and cognitive power, which includes the ability to process stimuli and produce verbal and motor responses. An altered state of consciousness usually refers to varying states of unconsciousness that may be momentary or may extend for hours, for days, or indefinitely. Unconsciousness is depressed cerebral function—the inability to respond to sensory stimuli and have subjective experiences. Coma is defined as a state of unconsciousness from which the patient cannot be roused even with powerful stimuli. Levels of Consciousness. Assessment of LOC remains the earliest indicator of improvement or deterioration in neurological status. LOC is determined by observations of the child’s responses to the environment. When it is being assessed in young children, it is often useful to have a parent present to help elicit a response. An infant or child may not respond the same in an unfamiliar environment or to an unfamiliar voice as to a parent or close caregiver. Children older than 3 years of age should be able to give their name, although they may not be cognizant of place or time. Other diagnostic tests, such as motor activity, reflexes, and vital signs, are more variable and do not necessarily directly parallel the depth of the comatose state. The most consistently used terms are described in Box 50.2. Coma Assessment. Several scales have been devised in an attempt to standardize the description and interpretation of the degree of depressed consciousness. The most popular of these is the Glasgow Coma Scale (GCS), which consists of a three-part assessment: eye opening, verbal response, and motor response (Figure 50.2). Numeric values of 1 through 5 are assigned to the levels of response in each category. The sum of these numeric values provides an objective measure of the patient’s LOC. A person with an unaltered LOC would score the highest, 15; a score of 8 or below is generally accepted as a definition of coma; the lowest score, 3, indicates severe head injury and deep, unresponsive coma or even brain death. A decrease in the GCS score indicates a deterioration in the patient’s condition. 1338 UNIT 12 BOX 50.1 Health Conditions of Children Clinical Manifestations of Increased Intracranial Pressure in Infants and Children Infants Tense, bulging fontanel Separated cranial sutures Macewen sign (cracked-pot sound on percussion) Irritability and restlessness Drowsiness, increased sleeping High-pitched cry Increased fronto-occipital circumference Distended scalp veins Poor feeding Crying when disturbed Setting-sun sign Children Headache Nausea Forceful vomiting Diplopia, blurred vision BOX 50.2 Levels of Consciousness Full consciousness—Awake and alert; oriented to person, place, and time; behaviour appropriate for age Confusion—Impaired decision making Disorientation—Disorientation to time and place, decreased level of consciousness Lethargy—Limited spontaneous movement, sluggish speech, drowsy, falling asleep quickly Obtundation—A severe reduction in LOC; the child arouses with very strong stimulus but is close to a comatose state Stupor—Remaining in a deep sleep, responsive only to vigorous and repeated stimulation or moaning responses to stimuli Coma—No motor or verbal response or extension posturing to noxious (painful) stimuli Persistent vegetative state (PVS)—Permanently lost function of the cerebral cortex; eyes following objects only by reflex or when attracted to the direction of loud sounds, all four limbs spastic but can withdraw from painful stimuli, hands showing reflexive grasping and groping, face grimacing, some food may be swallowed, groaning or crying but without uttering any words Neurological determination of death (NDD), previously known as brain death, is defined as the irreversible loss of the capacity for consciousness combined with the irreversible loss of all brainstem functions, including the capacity to breathe (Trillium Gift of Life Network, 2010). The criteria for NDD are listed in the Guidelines box: Neurological Determination of Death in Canada. GUIDELINES Neurological Determination of Death in Canada The following minimum clinical criteria are required for neurological determination of death (NDD): 1. Proof of etiology that is capable of causing neurological death (in the absence of reversible conditions capable of imitating neurological death) 2. Absence of reversible causes of coma, or confounding factors including: a. Unresuscitated shock b. Low core body temperature <34°C (or <36°C for term newborns) Seizures Indifference, drowsiness Decline in school performance Diminished physical activity and motor performance Increased sleeping Inability to follow simple commands Lethargy Late Signs in Infants and Children Bradycardia Decreased motor response to commands Decreased sensory response to painful stimuli Alterations in pupil size and reactivity Flexion or extension posturing Cheyne-Stokes respirations Papilledema Decreased consciousness Coma c. Treatable metabolic/endocrine/electrolyte disturbances (including hypernatremia, hypoglycemia, severe hypophosphatemia, liver and/or renal dysfunction) d. Peripheral nerve or muscle dysfunction due to disease or neuromuscular blocking agents (e.g., pancuronium, succinylcholine) e. Central nervous system (CNS) depressants/significant drug intoxications (e.g., alcohol, barbiturates, sedatives)—Note that therapeutic levels of anticonvulsants, sedatives, and analgesics do not preclude the diagnosis. 3. Absence of brainstem reflexes/absence of bilateral movement, both spontaneous and in response to stimulation (including seizures). Spinal cord reflexes are exempt. Deep pain testing must include all extremities and above the clavicles. 4. Absence of respiratory effort, as established by apnea testing Source: Trillium Gift of Life Network (TGLN). (2010). Neurological determination of death (NDD). https://www.giftoflife.on.ca/resources/pdf/ Neurological%20Determination%20of%20Death%20New%20EN.pdf. Neurological Examination The purpose of the neurological examination is to establish an accurate, objective baseline of neurological information. It is essential that the neurological examination be documented in a fashion that can be reproduced by others. This allows for a comparison of the findings so the observer can detect subtle changes in the neurological status that might not otherwise be evident. Descriptions of behaviours should be simple, objective, and easily interpreted—for example: “Drowsy but awake and oriented to person, place, and time”; “Sleepy but arousable with vigorous physical stimuli. Pressure to nail base of right hand results in upper extremity flexion/lower extremity extension.” Vital Signs. Pulse, respiration, and blood pressure provide information regarding the adequacy of circulation and the possible underlying cause of altered consciousness. Altered autonomic activity occurs most significantly in cases of deep coma, encephalopathy, or brainstem lesions. Body temperature is often elevated, and sometimes the elevation may be extreme. High temperature is most frequently a sign of an acute infectious process or heat stroke but may be caused by ingestion of some medications (especially salicylates, alcohol, and barbiturates) or CHAPTER 50 NEUROLOGICAL ASSESSMENT Size Right Reaction Pupils Size Left Reaction GLASGOW COMA SCALE Eyes open Best motor response 1   Brisk   Sluggish   No reaction C  Eye closed by swelling Spontaneously 4 To speech 3 To pain 2 None 1 Obeys commands 6 Localizes pain 5 Flexion withdrawal 4 Flexion abnormal 3 Extension 2 None 1 2 years Best response to auditory and/or visual stimulus 2 3 4 6 7 Usually record best arm or ageappropriate response 8 Pupil scale (mm) 2 years 5 Confused 4 4 Cries, consolable Inappropriate words 3 3 Inappropriate persistent cry Incomprehensible words 2 2 Agitated, restless None 1 1 No response 5 Smiles, listens, follows Endotracheal tube or trach T COMA SCALE TOTAL LOC Alert/oriented  4 Sleepy Irritable Comatose Disoriented Combative Lethargic Awake Sleeping Drowsy Agitated 1339 to describe what is being observed rather than placing a label on it because the traditional terms are often used and interpreted incorrectly. Periodic or irregular breathing is an ominous sign of brainstem (especially medullary) dysfunction that often precedes complete apnea. The odour of the breath may provide additional clues (e.g., the fruity, acetone odour of ketosis; the foul odour of uremia; the fetid odour of hepatic failure; or the odour of alcohol). 5 Orientation HAND GRIP Equal Unequal R_____L Weakness Neurological Conditions MUSCLE TONE Normal Arching Spastic Flaccid Weak Decorticate Decerebrate Other __________ FONTANEL/ WINDOW Soft Flat Sunken Tense Bulging Closed Other __________ EYE MOVEMENT Normal Nystagmus Strabismus Other __________ MOOD/AFFECT Happy Content Quiet Withdrawn Sad Flat Hostile Fig. 50.2 Pediatric coma scale. LOC, Level of consciousness. by intracranial bleeding, especially subarachnoid hemorrhage. Hypothalamic involvement may cause elevated or decreased temperature. Some infection may produce hypothermia. The pulse varies and may be rapid, slow and bounding, or feeble. Blood pressure may be normal, elevated, or at shock levels. The Cushing reflex, or pressor response, causes a slowing of the pulse and an increase in blood pressure and is uncommon in children; when it occurs it is a very late sign of increased ICP. Medications may affect the vital signs. For assessment purposes, actual changes in pulse and blood pressure are more important than the direction of the change. Slow, deep breathing is often seen in heavy sleep caused by sedatives, after seizures (postictal), or in cerebral infections. Slow, shallow breathing may result from use of sedatives or opioids. Hyperventilation with neurological compromise (deep and rapid respirations) is usually a result of metabolic acidosis or abnormal stimulation of the respiratory centre in the medulla caused by salicylate poisoning, hepatic coma, or Reye syndrome (RS). Breathing patterns have been described with a number of terms (e.g., apneustic, cluster, ataxic, Cheyne-Stokes). However, it is better Skin. The skin should be evaluated for colour (such as pallor, cyanosis, erythema, or jaundice), temperature, and turgor. In addition, the skin may offer clues to the cause of unconsciousness. The body surface should be examined for signs of injury (lacerations, ecchymosis, or hematoma), needle marks, petechiae, bites, and ticks. Evidence of toxic substances may be found on the hands, face, mouth, and clothing— especially in small children. Eyes. Pupil size and reactivity are assessed (Figure 50.3). Pupils either do or do not react to light. Pinpoint pupils are commonly observed in poisoning, such as opiate or barbiturate poisoning, or in brainstem dysfunction. Widely dilated and reactive pupils are often seen after seizures and may involve only one side. Dilated pupils may also be caused by eye trauma. Widely dilated and fixed pupils suggest paralysis of cranial nerve III secondary to pressure from herniation of the brain through the tentorium. A unilateral fixed pupil usually suggests a lesion on the same side. If pupils are fixed bilaterally for more than 5 minutes, it is usually assumed that there is brainstem damage. Dilated and nonreactive pupils are also seen in hypothermia, anoxia, ischemia, poisoning with atropinelike substances, or prior instillation of mydriatic medications. NURSING ALERT The sudden appearance of a fixed and dilated pupil(s) is a neurosurgical emergency. The description of eye movements should indicate whether one or both eyes are involved and how the reaction was elicited. The parents should be asked about pre-existing strabismus, which will cause the eyes to appear normal under compromise. Post-traumatic strabismus indicates cranial nerve VI damage. Special tests, usually performed by qualified persons, include the following: Doll’s head manoeuvre—Elicited by rotating the child’s head quickly to one side and then to the other. Conjugate (paired, or working together) movement of the eyes in the direction opposite to the head rotation is normal. Absence of this response suggests dysfunction of the brainstem or oculomotor nerve (cranial nerve III). NURSING ALERT Any tests that require head movement should not be attempted until after cervical spine injury has been ruled out. Caloric test, or oculovestibular response (RS)—Elicited with the child’s head up (head of bed is elevated 30 degrees) by irrigating the external auditory canal with 10 mL of ice water for 20 seconds, which normally causes conjugate movement of the eyes toward the side of stimulation. This response is lost when the pontine centres are impaired, thus providing important information in assessment of the comatose patient. Funduscopic examination—Reveals additional clues. Papilledema can occur with increased ICP, head injury, and encephalitis; this may be a later exam finding however. Papilledema is characterized 1340 UNIT 12 Health Conditions of Children A B C D E F Fig. 50.3 Variations in pupil size with altered states of consciousness. A: Ipsilateral pupillary constriction with slight ptosis. B: Bilateral small pupils. C: Midposition, light fixed to all stimuli. D: Bilateral dilated and fixed pupils. E: Dilated pupils, left eye abducted with ptosis. F: Pinpoint pupils. by optic disc swelling, indistinct optic disc margins, hemorrhage, tortuosity of vessels, and absence of venous pulsations. The presence of preretinal (subhyaloid) hemorrhages in children is almost invariably a result of acute trauma with intracranial bleeding, usually subarachnoid or subdural hemorrhage. Motor Function. Observing spontaneous activity, posture, and response to painful stimuli provides clues to the location and extent of cerebral dysfunction. Even subtle movements (e.g., the outward rotation of a hip) should be noted and the child observed for other signs. Asymmetrical movements of the limbs or absence of movement suggests paralysis. In hemiplegia, the affected limb lies in external rotation and will fall uncontrollably when lifted and allowed to drop. In patients with cerebellum abnormalities, heel-to-toe walking is difficult. Patients with cerebellar ataxia have an unsteady, broad-based gait. These observations should be described rather than labelled. In the deeper comatose states there is little or no spontaneous movement, and the musculature tends to be flaccid. There is considerable variability in the motor behaviour in lesser degrees of coma. For example, the child may be relatively immobile or restless and hyperkinetic; muscle tone may be increased or decreased. Tremors, twitching, and spasms of muscles are common observations. The child may display purposeless movements. Combative behaviour is common. Hyperactivity is more common in acute febrile and toxic states than in cases of increased ICP. Seizures are common in children and may be present from any cause. Any repetitive or seizure like movements should be described precisely. ones. Decorticate or flexion posturing (Figure 50.4, A) is seen with severe dysfunction of the cerebral cortex or with lesions to corticospinal tracts above the brainstem. Typical flexion posturing includes rigid flexion, with arms held tightly to the body; flexed elbows, wrists, and fingers; plantar flexed feet; legs extended and internally rotated; and possibly fine tremors or intense stiffness. Decerebrate posture or extension posturing (see Figure 50.4, B) is a sign of dysfunction at the level of the midbrain or lesions to the brainstem. It is characterized by rigid extension and pronation of the arms and legs, flexed wrists and fingers, clenched jaw, extended neck, and possibly an arched back. Unilateral extension posturing is often caused by tentorial herniation. Posturing may not be evident when the child is relaxed but can usually be elicited by applying painful stimuli, such as a blunt object pressed on the base of the nail. Noxious stimuli (e.g., suctioning) can elicit a response, as may turning or touching the patient. When the A NURSING ALERT Lack of response to painful stimuli is abnormal and should be reported immediately. Posturing. Primitive postural reflexes emerge as cortical control over motor function is lost in brain dysfunction. These reflexes are evident in posturing and motor movements directly related to the area of the brain involved. Posturing reflects a balance between the lower exciting and the higher inhibiting influences, and strong muscles overcoming weaker B Fig. 50.4 A: Flexion posturing. B: Extension posturing. CHAPTER 50 1341 sodium, potassium, chloride, calcium, and bicarbonate) tests; clotting studies, hematocrit, a complete blood count; liver function tests; blood cultures if there is fever; urine toxicology screen; and blood lead levels if clinically indicated. An electroencephalogram (EEG) may provide important information. For example, generalized random, slow activity suggests suppressed cortical function, and localized slow activity suggests a space-occupying lesion such as a hematoma, tumour, or infectious process. A flat tracing is one of the criteria used as evidence of NDD. Examination of spinal fluid is carried out when toxic encephalopathy or infection is suspected. Lumbar puncture is ordinarily delayed if intracranial hemorrhage is suspected and is contraindicated in the presence of ICP because of the potential for tentorial herniation. Auditory and visual evoked potentials are sometimes used in neurological evaluation of very young children. Visual evoked potentials can aid in evaluating visual abnormalities from the retina to the visual cortex, and brainstem auditory evoked potentials are useful for assessing hearing acuity and brainstem function. Both are particularly useful for detecting demyelinating diseases such as pediatric multiple sclerosis and neoplasms. Highly sophisticated tests are carried out with specialized equipment. Two imaging techniques, computed tomography (CT) and magnetic resonance imaging (MRI), assist in diagnosis by scanning both soft tissues and solid matter. Most of these tests are outlined in Table 50.1. Because such tests can feel threatening to children, the nurse is describing posturing, the stimulus needed to provoke the response is as important as the reaction. Reflexes. Testing of some reflexes may be of limited value. In general, the corneal, pupillary, muscle-stretch, superficial, and plantar reflexes tend to be absent in deep coma. The state of reflexes is variable in lighter grades of unconsciousness and depends on the underlying pathological process and the location of the lesion. Absence of corneal reflexes and presence of a tonic neck reflex are associated with severe brain damage. The Babinski reflex, in which the lateral portion of the foot is stroked, may be of value if it is found to be present consistently in children older than 1 year of age. A positive Babinski reflex is significant in assessment of pyramidal tract lesions when it is unilateral and associated with other pyramidal signs. A fluctuating Babinski reflex is often observed with seizures. NURSING ALERT Three key reflexes that demonstrate healthy neurological status in young infants are the Moro, tonic neck, and withdrawal (to painful stimuli) reflexes. Special Diagnostic Procedures Numerous diagnostic procedures are used for assessment of cerebral function. Laboratory tests that may help delineate the cause of unconsciousness include blood glucose, urea nitrogen, and electrolyte (pH, TABLE 50.1 Neurological Conditions Neurological Diagnostic Procedures Test Description Purpose Comments Lumbar puncture (LP) Spinal needle is inserted between L3–L4 or L4–L5 vertebral spaces into subarachnoid space; CSF pressure is measured, and a sample is collected for examination. Diagnostic—Measures spinal fluid pressure, obtains CSF for laboratory analysis Therapeutic—Injection of medication Contraindicated in patients with increased ICP or infected skin over puncture site Subdural tap Needle is inserted into anterior fontanel or coronal suture (midline to pupil). Helps rule out subdural effusions Removes CSF to relieve pressure Place infant in semi-erect position after subdural tap to minimize leakage from site; prevent child from crying if possible. Check site frequently for evidence of leakage. Ventricular puncture Needle is inserted into lateral ventricle via coronal suture (midline to pupil). Removes CSF to relieve pressure Risk of intracerebral or ventricular hemorrhage Electroencephalography (EEG) EEG records changes in electrical potential of brain. Electrodes are placed at various points to assess electrical function in a particular area. Impulses are recorded by electromagnetic pen or digitally. Detects spikes, or bursts of electrical activity that indicate the potential for seizures Used to determine neurological determination of death Patient should remain quiet during procedure; may require sedation Minimize external stimuli during procedure. Nuclear brain scan Radioisotope is injected intravenously, then counted and recorded after fixed time intervals. Radioisotope accumulates in areas where blood– brain barrier is defective. Identifies focal brain lesions (e.g., tumours, abscesses) Positive uptake of material with encephalitis and subdural hematoma Visualizes CSF pathways Requires intravenous (IV) access; patient may require sedation In healthy children or children with noncommunicating hydrocephalus, no retrograde filling of ventricles occurs. Areas of concentrated uptake of material are termed hot spots. Encephalography Pulses of ultrasonic waves are beamed through head; echoes from reflecting surfaces are recorded graphically. Identifies shifts in midline structures from their normal positions as a result of intracranial lesions May show ventricular dilation Simple, safe, rapid procedure Fontanel must be patent. Continued 1342 UNIT 12 TABLE 50.1 Health Conditions of Children Neurological Diagnostic Procedures—cont’d Test Description Purpose Comments Real-time ultrasonography (RTUS) RTUS is similar to CT but uses ultrasound instead of ionizing radiation. Allows high-resolution anatomical visualization in variety of imaging planes Produces images similar to CT scan Especially useful in newborn central nervous system issues Anterior fontanel must be patent. Radiography Skull films are taken from different views— lateral, posterolateral, axial (submentoventricular), half-axial. Shows fractures, dislocations, spreading suture lines, craniosynostosis Shows degenerative changes, bone erosion, calcifications Simple, noninvasive procedure Computed tomography (CT) scan Pinpoint X-ray beam is directed on horizontal or vertical plane to provide series of images that are fed into a computer and assembled in an image displayed on a video screen. CT uses ionizing radiation. Visualizes horizontal and vertical cross section of brain in three planes (axial, coronal, sagittal) Distinguishes density of various intracranial tissues and structures—congenital abnormalities, hemorrhage, tumours, demyelinating and inflammatory processes, calcification Requires IV access if contrast agent is used Patient may require sedation. Rapid Magnetic resonance imaging (MRI) MRI produces radiofrequency emissions from elements (e.g., hydrogen, phosphorus), which are converted to visual images by computer. Permits visualization of morphological feature of target structures Permits tissue discrimination unavailable with many techniques MRI is a noninvasive procedure except when IV contrast agent is used. No exposure to radiation occurs. Patient may require sedation. Parent or attendant can remain in room with child. MRI does not visualize bone detail or calcifications. No metal can be present in scanner. Positron emission tomography (PET) PET involves IV injection of positron-emitting radionucleotide; local concentrations are detected and transformed into visual display by computer. Detects and measures blood volume and flow in brain, metabolic activity, biochemical changes within tissue Requires lengthy period of immobility Minimum exposure to radiation occurs. Patient may require sedation. Digital subtraction angiography (DSA) Contrast dye is injected intravenously; computer “subtracts” all tissues without contrast medium, leaving clear image of contrast medium in vessels studied. Visualizes vasculature of target tissue Visualizes finite vascular abnormalities Safe alternative to angiography Patient must remain still during procedure; may require sedation. Single-photon emission computed tomography (SPECT) SPECT involves IV injection of photon-emitting radionuclide; radionuclides are absorbed by healthy tissue at a different rate than by diseased or necrotic tissue; data are transferred to a computer, which converts the image to film. Provides information regarding blood flow to tissues; analyzing blood flow to organ may help determine how well it is functioning Requires lengthy period of immobility Minimum exposure to radiation occurs. Patient may require sedation. nurse needs to prepare patients for the tests and provide support and reassurance during the tests (see Preparation for Diagnostic and Therapeutic Procedures, Chapter 44). Children who are old enough to understand require careful explanation of the procedure, the reason for the procedure, what they will experience, and how they can help. School-age children usually appreciate a more detailed description of procedures and an explanation of why contrast material is injected. Children unfamiliar with the machines can be shown a picture beforehand. Although radiographic examinations are not painful, the machinery is often so frightening in appearance that the child protests out of anxiety. It is important to stress to the child the importance of lying still for tests. This is especially true for CT and MRI, both of which require that the child’s head be placed within a special immobilizing device. Chin and cheek pads are sometimes used to prevent the slightest head movement, and straps are applied to the body to prevent a slight change in body position. The nurse can explain these events to a frightened child by comparing them to an astronaut’s preparation for a space flight. It is important to emphasize to the child that at no time is the procedure painful. Physical preparation for the diagnostic test may involve administration of a sedative. Many different agents are used for sedation of children undergoing neurological diagnostic procedures. Chloral hydrate or benzodiazepines have been used for decades as short-term sedative agents and remain safe methods in pediatric outpatient sedation CHAPTER 50 (Arlachov & Ganatra, 2012). Other sedative agents have been used safely, alone and in combination, for children and include intravenous (IV) sodium pentobarbital (Nembutal), IV fentanyl (Sublimaze), IV midazolam (Versed), and intranasal midazolam (Bhatt et al., 2015). Some adverse outcomes of pediatric outpatient sedation that have been reported include bradycardia, asystole, pulmonary aspiration, permanent neurological injury, and death (Bhatt et al., 2015). Propofol is a good sedation agent for diagnostic procedures because of its short induction and recovery time, but this medication should be used with caution because it can cause respiratory depression and apnea with little warning (Arlachov & Ganatra, 2012). Children scheduled to undergo sedation should be helped through the preparation and administration and be assured that someone will remain with them (if possible). Children need continual support and reinforcement during procedures in which they remain conscious. Vital signs and physiological responses to the procedure should be monitored throughout. Many diagnostic procedures performed on an outpatient basis require sedation, and children need recovery time and observation. The nurse should review written instructions with the parents before discharge. Children who have undergone a procedure with a general anaesthetic require postanaesthesia care, including positioning to prevent aspiration of secretions and frequent assessment of vital signs and LOC. In addition, other neurological functions such as pupillary responses, motor strength, and movement are tested at regular intervals. Any surgical wound resulting from the test should be checked for bleeding, CSF leakage, and other complications. Children who undergo repeated subdural taps should have their hematocrit level monitored to detect excessive blood loss from the procedure. NURSING CARE OF THE UNCONSCIOUS CHILD The unconscious child requires nursing observation, recording, and evaluation of changes in objective signs. These observations provide valuable information regarding the patient’s progress and often serve as a guide to diagnosis and treatment. Therefore, careful and detailed observations are essential for the patient’s welfare. In addition, vital functions must be maintained and complications prevented through conscientious and meticulous nursing care. The outcome of unconsciousness is variable and ranges from early and complete recovery, to death within a few hours or days, or persistent and permanent unconsciousness, or recovery with varying degrees of residual cognitive or physical disability. The outcome and recovery of the unconscious child may depend on the level of nursing care and observational skills. Emergency measures are directed toward ensuring a patent airway, breathing, and circulation; stabilizing the spine when indicated; treating shock; and reducing increased ICP. Delayed treatment often leads to increased damage. As soon as emergency measures have been implemented—and in many cases concurrently—therapies for specific causes are begun. Because nursing care is closely related to medical management, both are considered here. Continual observation of LOC, pupillary reaction, and vital signs is essential in the care of CNS disorders. The assessment frequency depends on the cause of unconsciousness and the progression of cerebral involvement. Intervals may be as short as every 15 minutes or as long as every 2 hours. Significant alterations should be reported immediately. Vital signs provide important information about the status of the unconscious child. The temperature is taken every 2 to 4 hours. Fevers can indicate an infective process, heat stroke, or brainstem or hypothalamic regulatory abnormalities. Tachycardia is common with fevers, hypovolemic shock, or heart failure, whereas increased ICP or myocardial injury can cause bradycardia. Tachypnea is associated with lung Neurological Conditions 1343 pathology, but quiet tachypnea indicates acidosis that can be associated with diabetic ketoacidosis or some poisonings (Sharma et al., 2010). The LOC is assessed periodically and includes evaluating pupillary size, equality, and reaction to light. Signs of meningeal irritation such as nuchal rigidity are assessed. Assessment of LOC includes response to vocal commands, spontaneous behaviour, resistance to care, and response to painful stimuli. Abnormal movement, changes in muscle tone or strength, and body position are noted. Seizure activity is described according to the duration and body areas involved. Pain management for the comatose child requires astute nursing observation and management. Signs of pain include changes in behaviour (e.g., increased agitation and rigidity, alterations in physiological parameters); increased heart rate, respiratory rate, and blood pressure; and decreased oxygen saturation. Since these findings are not specific for pain, the nurse should observe for their appearance during times of induced or suspected pain and their disappearance after the end of the inciting procedure or the administration of analgesia. A pain assessment record should be used to document indications of pain and the effectiveness of interventions (see Pain Assessment, Chapter 34). The use of opioids, such as morphine, to relieve pain is controversial because they may mask signs of altered consciousness or depress respirations. However, unrelieved pain activates the stress response, which can elevate ICP. To block the stress response, some health care providers advocate the use of analgesics, sedatives, and, in some cases such as head injury, paralyzing agents via continuous IV infusion. A frequently used combination is fentanyl, midazolam, and vecuronium (Norcuron). Acetaminophen (Tylenol) may also be an effective analgesic for mild to moderate pain. Regardless of which medications are used, adequate dosage and regular administration are essential to provide optimal pain relief. Other measures to relieve discomfort include providing a quiet, dimly lit environment; limiting visitors; preventing any sudden, jarring movements, such as banging into the bed; and preventing an increase in ICP. This last effort is most effectively achieved by proper positioning and prevention of the patient’s straining, such as during coughing, vomiting, suctioning, and defecating. Antiepileptic medications may be ordered for control of seizure activity. NURSING ALERT When opioids are used, bowel elimination must be closely monitored because of the potential constipating effect. Stool softeners should be given with laxatives as needed to prevent constipation (see Chapter 34). Respiratory Management Respiratory effectiveness is the primary concern in the care of the unconscious child, and establishing an adequate airway is always the first priority. Carbon dioxide has a potent vasodilating effect and will increase cerebral blood flow (CBF) and ICP. Cerebral hypoxia that lasts longer than 4 minutes nearly always causes irreversible brain damage. NURSING ALERT Respiratory obstruction and subsequent compromise lead to cardiac arrest. Maintaining an adequate, patent airway is of critical importance. Children in lighter states of coma may be able to cough and swallow, but those in deeper states are unable to handle secretions, which tend to pool in the throat and pharynx. Dysfunction of cranial nerves IX and X places the child at risk for aspiration and cardiac arrest; the child needs 1344 UNIT 12 Health Conditions of Children to be positioned to prevent aspiration of secretions and the stomach emptied to reduce the likelihood of vomiting. In infants, blockage of air passages from secretions can happen in seconds. In addition, upper airway obstruction from laryngospasm is a frequent complication in comatose children. An oral airway can be used for the child who has a temporary loss of consciousness, such as after a contusion, seizure, or anaesthesia. For children who remain unconscious for a longer time, a nasotracheal or orotracheal tube is inserted to maintain the open airway and facilitate removal of secretions. Insertion of an endotracheal tube (ET) should be considered when a child has a GCS of less than 8, evidence of herniation, apnea, or inability to maintain an airway. A tracheostomy is performed in cases in which laryngoscopy for introduction of an ET would be difficult or for a child who needs long-term ventilator support. Suctioning is used only as needed to clear the airway, exerting care to prevent increasing ICP. Signs of respiratory distress may be an indication for ventilatory assistance. When the respiratory centre is involved, mechanical ventilation is usually indicated (see Chapter 45). Blood gas analysis is performed regularly, and oxygen is administered when indicated. Moderately severe hypoxia and respiratory acidosis are often present but are not always evident from clinical manifestations. Hyperventilation frequently accompanies unconsciousness and may lead to respiratory alkalosis, or it may represent the body’s attempt to compensate for metabolic acidosis. Thus blood gas and pH determinations are essential guides for therapy. Chest physiotherapy is carried out on a regular basis, and the child’s position is changed at least every 2 hours to prevent pulmonary complications. Intracranial Pressure Monitoring An acute rise in ICP can cause secondary brain injury; the management of the child with increased ICP is a complex and important task. ICP monitoring is used to guide therapy and provides information on intracranial compliance, cerebrovascular status, and cerebral infusion. Nonetheless, ICP monitoring is an invasive procedure that has associated risks, including infections, hemorrhage, malfunction, and obstruction. More research is needed to provide further evidence of the efficacy of early detection of raised ICP and to develop treatment interventions that would improve cerebral perfusion and reduce brain injury (Forsyth et al., 2015). When a CSF obstruction causes increased ICP, a ventricular tap to drain excess CSF will provide relief quickly and effectively decrease the ICP. Evacuation of a hematoma reduces pressure from this source. Indications for inserting an ICP monitor are as follows: • GCS evaluation of less than 8 • GCS evaluation greater than 8 with respiratory assistance • Deterioration of condition • Subjective judgement regarding clinical appearance and response (Bhalla et al., 2012) Four major types of ICP monitors are as follows: 1. Intraventricular catheter with fibroscopic sensors attached to a monitoring system 2. Subarachnoid bolt (Richmond screw) 3. Epidural sensor 4. Anterior fontanel pressure monitor Direct ventricular pressure measurement with an intraventricular catheter remains the gold standard of ICP monitoring. Placement of the intraventricular catheter and subarachnoid bolt occurs through a burr hole in the skull. The intraventricular catheter is introduced into the lateral ventricle on the nondominant side, if known. The subarachnoid bolt is placed in the subarachnoid space, and the epidural sensor is placed between the dura and the skull. The intraventricular catheter has the advantage of providing a means for recalibration when measurement drift occurs; both the catheter and the bolt can be used for therapeutic CSF drainage to reduce pressure. A drainage bag attached to the system is kept at the level of the ventricles and can be lowered to decrease ICP. The placement of the bolt is not adjusted by anyone except the neurosurgeon who placed the device. The neurosurgeon should be notified if a satisfactory waveform is not observed. NURSING ALERT The bolt is stabilized with dressings, but these are not changed or disturbed, even to check the site. However, they can be reinforced. An epidural sensor provides a readout of the ICP with a stopcock assembly and transducer. In infants, a fontanel transducer can be used to detect impulses from a pressure sensor and convert them to electrical energy. The electrical energy is then converted to visible waves or numeric readings on an oscilloscope. ICP measurement from the anterior fontanel is noninvasive but may prove to be inaccurate if the equipment is poorly placed or inconsistently recalibrated. ICP can be increased by instilling solutions; therefore, antibiotics are administered intravenously if a positive CSF culture is obtained. CSF is a body fluid, thus routine precautions are implemented according to institutional policy. Nurses caring for patients with intracranial monitoring devices must be acquainted with the system, assist with insertion, interpret the monitor readings, and be able to distinguish between danger signals and mechanical dysfunction. Because systematic blood pressure, ICP, and therefore cerebral perfusion pressure (CPP) are normally lower in children, the child’s age must be considered when deciding what constitutes an abnormally high ICP or abnormally low ICP. Managing Intracranial Pressure. In cases of high levels of increased ICP, procedures tend to trigger reactive pressure waves in many patients. For example, increased intrathoracic or abdominal pressure will be transmitted to the cranium. Particular care should be taken in positioning these patients to avoid neck vein compression, which may further increase ICP by interfering with venous return. The child can be propped to one side or the other, and the use of an alternating-pressure mattress reduces the chance of prolonged pressure to vulnerable areas. Frequent clinical assessment of the child cannot be replaced by an ICP monitoring device. NURSING ALERT The head of the bed is elevated to 15 to 30 degrees, and the child is positioned so that the head is maintained in midline to facilitate venous drainage and avoid jugular compression. It is important to avoid activities that may increase ICP by causing pain or emotional stress. Clustering nursing activities together and minimizing environmental stimuli by decreasing noxious procedures help to control ICP. Gentle range-of-motion exercises can be carried out but should not be performed vigorously. Nontherapeutic touch can cause an increase in ICP. Any disturbing procedures to be performed should be scheduled to take advantage of therapies that reduce ICP, such as osmotherapy and sedation. Environmental noise should be minimized or eliminated to the degree possible. Assessment and intervention to relieve pain are important nursing actions to decrease ICP. Suctioning and chest percussion are poorly tolerated and are contraindicated unless concurrent respiratory issues exist. Hypoxia and the CHAPTER 50 Valsalva manoeuvre associated with cough both acutely elevate ICP. Vibration, which does not increase ICP, accomplishes excellent results and should be tried first if treatment is needed. If suctioning is necessary, it should be brief and preceded by hyperventilation with 100% oxygen, which can be monitored during suctioning with pulse oximetry to determine oxygen saturation. Several medical measures are available to treat increased ICP resulting from cerebral edema. Osmotic diuretics may provide rapid relief in emergency situations. Although their effect is transient, lasting only about 6 hours, they can be lifesaving in emergencies. These substances are rapidly excreted by the kidneys and carry with them large quantities of sodium and water. Mannitol or hypertonic saline (3% solution) or both measures are administered intravenously and are the most frequently used for rapid reduction (Kochanek & Bell, 2020). The infusion is generally given slowly but may be pushed rapidly in cases of herniation or impending cerebral herniation. Because of the profound diuretic effect of the medication, an in-dwelling catheter is inserted to ensure bladder emptying. Adrenocorticosteroids are not recommended for cerebral edema secondary to head trauma. Arterial carbon dioxide (PaCO2) should be maintained at 25 to 30 mm Hg to produce vasoconstriction, which reduces CSF, thereby decreasing ICP. Nutrition and Hydration In the unconscious child, fluids and calories are supplied initially via the IV route (see Chapter 44). An IV infusion is started early, and the type of fluid administered is determined by the patient’s general condition. Fluid therapy requires careful monitoring and adjustment based on neurological signs and electrolyte determinations. The goal of fluid therapy is euvolemia (normal blood volume). Often, comatose children are unable to cope with the same amounts of fluid they could tolerate at other times, and overhydration must be avoided to prevent fatal cerebral edema. When cerebral edema is a threat, fluids may need to be restricted to reduce the chance of fluid overload. Skin and mucous membranes need to be examined for signs of dehydration. Adjustments to fluid administration are based on urinary output, serum electrolytes and osmolarity, blood pressure, and arterial filling pressure. Observation for signs of altered fluid balance related to abnormal pituitary secretions is also a part of nursing care. Long-term nutrition is provided with a balanced formula via a nasogastric or gastrostomy tube. Altered Pituitary Secretion. An altered ability to handle fluid loads is attributed in part to the syndrome of inappropriate antidiuretic hormone secretion (SIADH) and diabetes insipidus (DI) resulting from hypothalamic dysfunction (see Chapter 51, Syndrome of Inappropriate Antidiuretic Hormone). SIADH frequently accompanies CNS diseases such as head injury, meningitis, encephalitis, brain abscess, brain tumour, and subarachnoid hemorrhage. In the patient with SIADH, scant quantities of urine are excreted, electrolyte analysis reveals hyponatremia and hyposmolality, and manifestations of overhydration are evident. It is important to evaluate all parameters, since the reduced urine output might be erroneously interpreted as a sign of dehydration. The treatment of SIADH consists of restriction of fluids until serum electrolytes and osmolality return to normal levels. DI may occur after intracranial trauma. In DI there are large amounts of diluted urine and the accompanying danger of dehydration. Adequate replacement of fluids is essential, and observation of electrolyte balance is necessary to detect signs of hypernatremia and hyperosmolality. Exogenous vasopressin may be administered. Neurological Conditions 1345 Medications The cause of unconsciousness determines specific medication therapies. Children with infectious processes such as meningitis or encephalitis may be given antibiotics appropriate to the disease and the infecting organism. Corticosteroids are prescribed for inflammatory conditions, CNS demyelinating diseases, and edema. Cerebral edema is an indication for osmotherapy with osmotic diuretics. Sedatives or antiepileptics are prescribed for seizure activity. MEDICATION ALERT Sedation in the combative child provides amnesic and anxiolytic properties in conjunction with a paralytic agent. The combination decreases ICP and allows treatment of cerebral edema. Usual medications include morphine, midazolam, and pancuronium (Pavulon). Midazolam is attractive because of its short half-life. The management of increased ICP using a barbiturate-induced deep coma is debated among practitioners. Barbiturates are currently reserved for the reduction of increased ICP when all else has failed. Barbiturates decrease the cerebral metabolic rate for oxygen and protect the brain during times of reduced CPP. Barbiturate comas require extensive monitoring, cardiovascular and respiratory support, and ICP monitoring to assess response to therapy. Paralyzing agents such as pancuronium also may be needed to aid in performing diagnostic tests, improving effectiveness of therapies, and reducing risks of secondary complications. Elevation of ICP or heart rate of patients who are being given paralyzing agents or are under sedation may indicate the need for another dose of either or both medications. Thermoregulation Hyperthermia often accompanies cerebral dysfunction; if it is present, measures should be implemented to reduce the temperature to prevent brain damage and to reduce metabolic demands generated by the increased body temperature. Medically induced hypothermia assists in controlling ICP and may result in an improved outcome. Antipyretic agents are the method of choice for fever reduction; cooling devices should be used for hyperthermia. Laboratory tests and other methods are used in an attempt to determine the cause of the hyperthermia. Elimination A urinary catheter is usually inserted during the acute phase, although diapers may be used and weighed to record urine output. The child who formerly had bowel and bladder control is generally incontinent. If the child remains comatose for a long period, the in-dwelling catheter may be removed and periodic bladder emptying accomplished by intermittent catheterization. Stool softeners are usually sufficient to maintain bowel function, but suppositories or enemas may be needed occasionally for adequate elimination and to prevent fecal impaction. The passage of liquid stool after a period of no bowel activity is usually a sign of an impaction. To avoid this preventable condition, daily recording of bowel activity is essential. Hygienic Care Routine measures for cleansing to maintain skin integrity are an integral part of nursing of the unconscious child. The child who is unable to move is prone to developing tissue breakdown. To help prevent this, the child can be placed on an alternating-pressure or water-filled mattress, which alleviates pressure on vulnerable areas. Assessment of pressure ulcer risk can be calculated using the modified pediatric Braden QD Scale (see Additional Resources). 1346 UNIT 12 Health Conditions of Children Mouth care should be performed at least twice daily, because the mouth tends to become dry or coated with mucus. The teeth should be carefully brushed with a soft toothbrush or cleaned with gauze saturated with saline. Commercially prepared cleansing devices, such as Toothettes, are convenient for cleansing the mouth and teeth. Lips can be coated with ointment or other water-based preparations to protect them from drying, cracking, or blistering. Glycerin swabs should not be used, as they break down tooth enamel. The deeply comatose child is also prone to eye irritation. The corneal reflexes are absent; thus the eyes are easily irritated or damaged by linen, dust, or other substances that may come in contact with them. There is excessive dryness as a result of incomplete closure of the eyes or decreased secretions, especially if the child is undergoing osmotherapy to reduce or prevent brain edema. NURSING ALERT The eyes should be examined regularly and carefully for early signs of irritation or inflammation. Artificial tears (methylcellulose) are placed in the eyes every 1 to 2 hours. Eye dressings may sometimes be needed to protect the eyes from possible damage. Positioning and Exercise The unconscious child needs to be positioned to prevent aspiration of saliva, nasogastric secretions, and vomitus and to minimize ICP. The head of the bed is elevated, and the child is placed in a side-lying or semiprone position. A small, firm pillow is placed under the head, and the uppermost limbs are flexed and supported with pillows. In the semiprone position, the child lies with the dependent arm at the side behind the body, the opposite side supported on pillows, and the uppermost arm and leg flexed and resting on the pillows. This position prevents undue pressure on the dependent extremities. The dependent position of the face encourages drainage of secretions and prevents the flaccid tongue from obstructing the airway. Normal range-of-motion exercises help maintain function and prevent contractures of joints. Exercises should be done gently and with full range of motion. A small rolled pad can be placed in the palms to help maintain proper position of the fingers; footboards or boots can be used to help prevent footdrop; and splinting may be needed to prevent severe contractures of the wrist, knee, or ankle in decerebrate children. Extremity splints and the child’s position should be changed every 1 to 2 hours. Stimulation Sensory stimulation is important in the care of the unconscious child. It helps arouse the temporarily unconscious or semiconscious child to the conscious state and orient the child in terms of time and place. Auditory and tactile stimulation are especially valuable. Tactile stimulation is not appropriate for the child in whom it may elicit an undesirable response. However, for other children, tactile contact often has a relaxing and calming effect. When the child’s condition permits, holding or rocking has a soothing effect and provides body contact needed by young children. Involving family members with the sensory stimulation can create a positive effect on the child and allows the family to participate in their care. The auditory sense is often present in a state of coma. Hearing is the last sense to be lost and the first one to be regained, thus the child should be spoken to as any other child. Conversation around the child should not include thoughtless or derogatory remarks. Soft music is used frequently to provide auditory stimulation. Singing the child’s favourite songs or reading a favourite story can help the child maintain contact with a familiar world. Playing songs or stories recorded in the parents’ voices can also provide a continuous source of familiar stimulation. Regaining Consciousness Awakening from a coma is a gradual process; however, sometimes children regain consciousness within a short time. Regaining orientation involves knowing person, place, and time, in that order. Certain behaviours have been observed when children awaken from the unconscious state. The stress and anxiety they appear to feel in a strange and unfamiliar environment are consistently expressed in silent and withdrawn behaviour. Children respond to basic questioning but usually do not display their prehospitalization personality and social behaviour until they are transferred from the critical care area. Family Support Helping the parents of an unconscious child cope with the situation can be especially difficult. They may